1Heat oven to 350°F. Spray 2-quart shallow casserole or 8-inch square glass baking dish with cooking spray. Make potatoes as directed on pouch using water, milk and butter.
2Meanwhile, in 12-inch nonstick skillet, melt remaining 1 tablespoon butter over medium-high heat. Add chicken and onion; cook 4 to 6 minutes, stirring frequently, until chicken is no longer pink in center. Stir in mixed vegetables, gravy and 2 teaspoons of the paprika. Cover; cook over medium-low heat 5 minutes, stirring frequently to prevent sticking.
3Stir sour cream into chicken mixture. Spoon into casserole. Spoon or pipe potatoes in 8 mounds around edge of casserole. Sprinkle potatoes with remaining 1/4 teaspoon paprika.
4Bake uncovered 25 to 35 minutes or until mixture bubbles around edge of casserole.